Poster: Nutrient Biology

Abs # 410: Regulation of a high-affinity nitrate transporter gene (AtNRT2.1) by nitrate and cadmium ions in roots of Arabidopsis thaliana

Presenter:	Singh, Santokh , santokh@interchange.ubc.ca
Authors	Singh, Santokh  (A)   Li, Vicar  (A)   Zis, Thalia  (A)   Chan, Mike  (A)
Affiliations:	(A): University of British Columbia

A high-affinity nitrate transporter gene (AtNRT2.1) was isolated from roots of Arabidopsis thaliana using reverse transcriptase-PCR. AtNRT2.1 transcripts were undetectable in roots of 6-weeks old hydroponically-grown Arabidopsis thaliana plants deprived of NO₃^- for one week. Exposure of the NO₃^-- deprived plants to NO₃^- (1 mM) increased the AtNRT2.1 transcript abundance to a maximum by 3 h, then declined to very low levels by 48 h. When CdCl₂ (10^-5 M) along with NO₃^- (1 mM) was supplied to the NO₃^-- deprived plants, a further increase in the AtNRT2.1 transcript abundance was observed. However, CdCl₂ (10^-5 M) alone did not increase the AtNRT2.1 transcript abundance in roots of NO₃^-- deprived plants. The role of cadmium ions in up-regulation of NO₃^-- induced AtNRT2.1 expression will be discussed.